BT has rolled out superfast broadband to an area covering 10m homes eight months ahead of deadline, after hiring hundreds of extra engineers and drafting in ex-services personnel to boost its workforce.

The group has reached its target of taking fibre from telephone exchanges to thousands of street cabinets from Bristol to Brixton comfortably ahead of its end-of-2012 deadline.

Ian Livingston, the chief executive, said: "Rolling out fibre is no easy task and so to have passed 10m premises in such a short time is fantastic. Our roll-out is one of the fastest in the world and our engineers deserve lots of credit."

As the top 1,000 BT managers prepare to share a £90m stock windfall pegged to rising cashflows, with Livingston in line to collect shares worth £5m, the group beat forecasts to report a 3% increase in underlying full year earnings to £6bn and raised the dividend to shareholders by 12%.

Adjusted revenues in the year to 31 March were down 4% to £19.31bn, slightly below the £19.33bn forecast. The adjustment included a £410m charge from a regulatory ruling in Germany.

Livingston said the target of more than £6bn for pre-tax earnings had been reached a year early. Underlying revenues would show an improving trend in 2013 and 2014.

The consumer division, BT Retail, signed up 589,000 UK broadband subscribers in the year to 31 March, against 702,000 at BSkyB, with both companies poaching customers from rivals including Virgin Media.

In the last quarter, 131,000 signed up for the BT Infinity fibre-to-the-cabinet product, which offers speeds of up to 76mbps and is being priced on a par with the fastest copper lines, meaning BT now has more than half a million fibre customers.

From 2013, the group plans to run fibre direct from telephone exchanges to premises across its existing fibre footprint. An all-fibre line would allow speeds of up to 300mbps, with a future potential for 1 gigabit per second.

The product will cost about £1,000 a line for installation, appealing to businesses but putting it out of reach of most householders.

The final dividend was increased 14% to 5.7p. Having agreed a payment plan in March to cover its £3.9bn pension deficit, BT announced more cash for shareholders, with a 10%-15% per year increase in dividends for the next three years.

"BT provides a level of stability and security that has so far been utterly absent in the rest of the telecom sector," said Robin Bienenstock, financial analyst at Bernstein Research. "The company and its shareholders have been handsomely rewarded for that."

Revenues at BT Openreach,which builds and operates the BT Group network, rose 4% to £5.1bn, while operating profit rose 8% to £1.36bn. Capital expenditure decreased 5%, because the investment in fibre was offset by lower spending on copper broadband.

Losses narrowed at BT Global Services, the division that builds networks for corporate clients, from £141m to £85m. Contracts worth £2bn were signed in the fourth quarter, with customers including Anglo American and Nato.

Revenue at BT Retail was down 4% in the year, with consumer revenues down 2%, the lowest decline in two years thanks to growth in broadband and BT Vision, the pay-TV service, which added 28,000 customers in the quarter, bringing its total to 700,000.